Implemented annotated local typing method without testing

src/autobigs/engine/structures/alignment.py

@@ -0,0 +1,17 @@
+from dataclasses import dataclass
+from numbers import Number
+
+@dataclass(frozen=True)
+class AlignmentStats:
+    percent_identity: float
+    mismatches: int
+    gaps: int
+    score: int
+
+@dataclass(frozen=True)
+class PairwiseAlignment:
+    reference: str
+    query: str
+    reference_indices: list[Number]
+    query_indices: list[Number]
+    alignment_stats: AlignmentStats